1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <uapi/linux/idxd.h>
#include "idxd.h"
#include "registers.h"
static struct idxd_desc *__get_desc(struct idxd_wq *wq, int idx, int cpu)
{
struct idxd_desc *desc;
struct idxd_device *idxd = wq->idxd;
desc = wq->descs[idx];
memset(desc->hw, 0, sizeof(struct dsa_hw_desc));
memset(desc->completion, 0, idxd->data->compl_size);
desc->cpu = cpu;
if (device_pasid_enabled(idxd))
desc->hw->pasid = idxd->pasid;
/*
* On host, MSIX vecotr 0 is used for misc interrupt. Therefore when we match
* vector 1:1 to the WQ id, we need to add 1
*/
if (!idxd->int_handles)
desc->hw->int_handle = wq->id + 1;
else
desc->hw->int_handle = idxd->int_handles[wq->id];
return desc;
}
struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype)
{
int cpu, idx;
struct idxd_device *idxd = wq->idxd;
DEFINE_SBQ_WAIT(wait);
struct sbq_wait_state *ws;
struct sbitmap_queue *sbq;
if (idxd->state != IDXD_DEV_ENABLED)
return ERR_PTR(-EIO);
sbq = &wq->sbq;
idx = sbitmap_queue_get(sbq, &cpu);
if (idx < 0) {
if (optype == IDXD_OP_NONBLOCK)
return ERR_PTR(-EAGAIN);
} else {
return __get_desc(wq, idx, cpu);
}
ws = &sbq->ws[0];
for (;;) {
sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE);
if (signal_pending_state(TASK_INTERRUPTIBLE, current))
break;
idx = sbitmap_queue_get(sbq, &cpu);
if (idx >= 0)
break;
schedule();
}
sbitmap_finish_wait(sbq, ws, &wait);
if (idx < 0)
return ERR_PTR(-EAGAIN);
return __get_desc(wq, idx, cpu);
}
void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc)
{
int cpu = desc->cpu;
desc->cpu = -1;
sbitmap_queue_clear(&wq->sbq, desc->id, cpu);
}
static struct idxd_desc *list_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie,
struct idxd_desc *desc)
{
struct idxd_desc *d, *n;
lockdep_assert_held(&ie->list_lock);
list_for_each_entry_safe(d, n, &ie->work_list, list) {
if (d == desc) {
list_del(&d->list);
return d;
}
}
/*
* At this point, the desc needs to be aborted is held by the completion
* handler where it has taken it off the pending list but has not added to the
* work list. It will be cleaned up by the interrupt handler when it sees the
* IDXD_COMP_DESC_ABORT for completion status.
*/
return NULL;
}
static void llist_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie,
struct idxd_desc *desc)
{
struct idxd_desc *d, *t, *found = NULL;
struct llist_node *head;
desc->completion->status = IDXD_COMP_DESC_ABORT;
/*
* Grab the list lock so it will block the irq thread handler. This allows the
* abort code to locate the descriptor need to be aborted.
*/
spin_lock(&ie->list_lock);
head = llist_del_all(&ie->pending_llist);
if (head) {
llist_for_each_entry_safe(d, t, head, llnode) {
if (d == desc) {
found = desc;
continue;
}
list_add_tail(&desc->list, &ie->work_list);
}
}
if (!found)
found = list_abort_desc(wq, ie, desc);
spin_unlock(&ie->list_lock);
if (found)
complete_desc(found, IDXD_COMPLETE_ABORT);
}
int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
{
struct idxd_device *idxd = wq->idxd;
struct idxd_irq_entry *ie = NULL;
void __iomem *portal;
int rc;
if (idxd->state != IDXD_DEV_ENABLED) {
idxd_free_desc(wq, desc);
return -EIO;
}
if (!percpu_ref_tryget_live(&wq->wq_active)) {
idxd_free_desc(wq, desc);
return -ENXIO;
}
portal = idxd_wq_portal_addr(wq);
/*
* The wmb() flushes writes to coherent DMA data before
* possibly triggering a DMA read. The wmb() is necessary
* even on UP because the recipient is a device.
*/
wmb();
/*
* Pending the descriptor to the lockless list for the irq_entry
* that we designated the descriptor to.
*/
if (desc->hw->flags & IDXD_OP_FLAG_RCI) {
ie = &idxd->irq_entries[wq->id + 1];
llist_add(&desc->llnode, &ie->pending_llist);
}
if (wq_dedicated(wq)) {
iosubmit_cmds512(portal, desc->hw, 1);
} else {
/*
* It's not likely that we would receive queue full rejection
* since the descriptor allocation gates at wq size. If we
* receive a -EAGAIN, that means something went wrong such as the
* device is not accepting descriptor at all.
*/
rc = enqcmds(portal, desc->hw);
if (rc < 0) {
percpu_ref_put(&wq->wq_active);
/* abort operation frees the descriptor */
if (ie)
llist_abort_desc(wq, ie, desc);
else
idxd_free_desc(wq, desc);
return rc;
}
}
percpu_ref_put(&wq->wq_active);
return 0;
}
|
